What is the Best Dose of Nature
and Green Exercise for Improving
Mental Health? A Multi-Study
J O B A R T O N A N D J U L E S P R E T T Y *
Interdisciplinary Centre for Environment and Society,
Department of Biological Sciences, University of Essex,
Colchester CO4 3SQ, U.K.
Received October 21, 2009. Revised manuscript received
March 12, 2010. Accepted March 15, 2010.
Green exercise is activity in the presence of nature. Evidence
shows it leads to positive short and long-term health
outcomes. This multistudy analysis assessed the best regime
self-esteem and mood (indicators of mental health). The
research used meta-analysis methodology to analyze 10 UK
studies involving 1252 participants. Outcomes were identified
through a priori subgroup analyses, and dose-responses were
assessed for exercise intensity and exposure duration. Other
subgroup analyses included gender, age group, starting health
status, and type of habitat. The overall effect size for improved
self-esteem was d ) 0.46 (CI 0.34-0.59, p < 0.00001) and for
mood d ) 0.54 (CI 0.38-0.69, p < 0.00001). Dose responses
for both intensity and duration showed large benefits from short
engagements in green exercise, and then diminishing but
esteem and mood; the presence of water generated greater
effects. Both men and women had similar improvements in self-
esteem after green exercise, though men showed a difference
for mood. Age groups: for self-esteem, the greatest change
the least change was in the young and old. The mentally ill
had one of the greatest self-esteem improvements. This study
confirms that the environment provides an important health
Ecosystems provide important services driven by provision-
ing, regulation, and support functions (1, 2). It is clear they
also provide a health service arising from direct activities in
of natural ecosystems to human population health may
obesity, mental ill-health, and other chronic diseases. Many
of these urgent health challenges are also connected to
in 1.9 million deaths worldwide annually (5), roughly 1 in 25
of all deaths. Preindustrial humans expend some 1000 kcal
on activity per day, whereas for modern humans the mean
is 300 kcal (6). Inactivity increases the likelihood of obesity
and reduces life expectancy. Such physical inactivity tracks
from childhood, and is a key risk factor in many chronic
diseases of later life (7). Mental health disorders are now
known to affect most people at some point in their lives,
with 16% of the general population affected at any given
sectors of the population undertake and sustain healthy
behaviors as early in life as possible (10).
Evidence shows that exposure to natural places can lead
from a window, being within natural places, or exercising in
these environments (11–13). At the population level, there
(14). Thus, green space is important for mental health and
regular engagement is linked with longevity and decreased
risk of mental ill-health (15). Yet as more than half of the
world’s population now live in urban settlements, daily
environmental contact is becoming rarer (16), suggesting
the growing importance of access to local greenspace for
both quality of life and the sustainability of towns and cities
(17, 18). It is also well-known that physical activity improves
both physical and mental health of all age groups (19–22).
Thus “green exercise”, consisting of activity in green places
(in the presence of nature), is predicted to generate positive
health outcomes (23–26), accrue ecological knowledge
(21, 22, 27, 28), foster social bonds (29), and influence
behavioral choices (11, 24–26, 30, 31). In economic terms,
there should be cost savings if natural places are both
Achieving good mental health is not just a reflection of
the absence of disease or disability. It comprises a balance
between self-satisfaction, independence, capability and
and adversity (34). Both self-esteem and mood are short-
and long-term determinants of mental health: both are
commonly assessed in green-exercise research. Self-esteem
is an evaluation of a person’s sense of worth or value (35),
and health (28, 36). There are further inverse relationships
between self-esteem and mental health (e.g., depression,
eating, participating in physical activities, not smoking, and
lower suicide risks (37).
Mood is an integral component of daily life and strongly
influences feelings of happiness, appreciating the moment,
coping with stressful situations, and quality of life (38, 39).
Mood is linked with physical health and is known to affect
the immune system and the onset of certain diseases (40).
Acute changes in mood are generally maintained for 2-4 h
post exercise, though this relatively short duration of
enhanced mood has a positive influence on quality of life
including more social interaction, improved productivity,
and better behavioral choices (39–41). Regular exercise
contributes to sustained chronic changes in mood. Thus,
both self-esteem and mood are regularly used to assess the
to value (42–44), and these scientific findings do not yet
appear to have influenced the planning of urban and rural
environments, priorities for public health, social care and
youth offender programs, nor recommendations for the
emergence of sustainable lifestyles. The evidence to date
incorporates different methodologies and variables mea-
sured, along with international differences in typologies of
greenspaces, length of activity programs, and primary
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research questions. Uncertainties remain on the ideal
duration and intensity of nature-based activities to improve
required to improve self-esteem and mood. The term “dose
duration of exposure, intensity of activity, and type of
Detailed research questions relate to physical activities
intensity affect self-esteem and mood?; 3. How do different
green habitats (e.g., urban green space, countryside, water-
side, wilderness, woodlands) affect self-esteem and mood?
participant characteristics (e.g., children, adult, elderly;
using standardized meta-analysis methods to assess the
impact of green exercise on self-esteem and mood. This
enabled us to determine the most effective regime(s) for a
on the combined benefits of both variables and does not
assess the separate contributions of nature and physical
activity on mental health.
Materials and Methods
Study Selection. Ten studies undertaken by the University
of Essex over the past six years were selected for inclusion.
all used identical measurement tools to analyze changes in
self-esteem and mood after an acute exposure to green
exercise. However, to ensure validity of the overall analysis
standardized meta-analysis methods were used.
state measures and can be easily manipulated in the short
lifestyle choices. None of the studies used randomized
controlled trials or incorporated control groups where
participants were exposed to nature without exercising or
exercised in nongreen environments. All 1252 participants
were self-selecting using an opportunistic sampling meth-
odology and took part only in one study. We had full access
to all primary data, including pre- and post- mean values,
sample sizes, paired groups t-value, effect directions and
information on the nature of the intervention, participants
and location type (Table 1). This study does not therefore
include a large variety of studies from different research
Self-Esteem and Mood Measures. The Rosenberg Self-
Esteem Scale (RSE) is the most widely used and popular
self-esteem measure (45, 46). Many researchers regard the
scale as the standard against which other measures of self-
was measured immediately pre- and postactivity or inter-
vention using the one-page 10-item RSE scale.
The instrument used to quantify changes in mood was
the Profile of Mood States (POMS) standardized short-form
(47). POMS is the primary instrument for measuring mood
were taken in all these studies immediately pre- and
postactivity or intervention.
Statistical Analysis. Standardised meta-analysis meth-
odologies were used to assess changes in self-esteem and
mood data pre- and post- green exercise interventions.
the pre- and postintervention values for both self-esteem
and total mood disturbance (TMD) (46, 47). The Compre-
were pooled to calculate an overall intervention effect
estimate. This represents the weighted average of the
combined individual intervention effects and the inverse-
variance method was used to assign weights to each study.
Thus, larger studies with smaller standard errors were given
This reduced the imprecision of the pooled-effect estimate.
It was assumed that the various studies involved in the
analysis were measuring different but related intervention
effects, and thus the combined intervention effect estimates
were calculated using a random-effects model meta-analysis
was used to inspect bias, and 95% confidence intervals were
calculated on the basis of the standard error of the pooled
intervention effect. Statistical significance was set at p < 0.05.
TABLE 1. Descriptive Data on the Green Exercise Interventions Included in the Meta-Analysisa
participantstype of activities type of environmentscohort
1 256cycling, gardening,
walking, fishing, boating,
and woodland, urban green,
and woodland, wild habitats
forest and woodland
and woodland, waterside, wild
forest and woodland
individuals choosing to
engage in GE activities
2 153 individuals at NT sites
visitors to care farms
members of local mind
6 86walking individuals choosing to
engage in GE activities
individuals at urban flower
visitors to care farms
individuals responsible for
7 447walking urban green
walking, water based (sailing)
wild habitats, waterside
aNote: These studies were conducted with (1) Countryside Recreation Network, (2) National Trust, (3) National Care
Farming Initiative, (4) University of Essex, (5) Mind, (6) Highwoods Country Park, (7) Royal Horticultural Society, (8) LEAF,
(9) Wilderness Foundation, and (10) local allotment societies.
3948 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 44, NO. 10, 2010
using both Q statistic and degrees of freedom (53).
differing cohorts, type of green space, exposure duration or
exercise intensity, a series of predefined a priori subgroup
analyses were conducted. This allowed the exploration of
possible sources of heterogeneity by identifying modifiers.
Selection was based on causal mechanisms, magnitude of
effects and statistical significance (54). In accordance with
recommendations, all subgroup analyses were justified by
and self-esteem/mood. The subgroup analyses identified
day; 2. exercise intensity: low (<3 METs (metabolic equiva-
lent)), moderate (3-6 METs-) and vigorous (>6 METs) (55);
3. type of green space: urban green, countryside/farmland,
forest/woodland, waterside, and wilderness-type habitats;
4. gender: female or male; 5. age groups: <30 years, 31-50,
or with existing mental health problems.
Effect of Green Exercise. The multistudy analysis of differ-
are shown in Figures 1a and b. The overall effect size for
and significant heterogeneity was found between estimates
for change in TMD was d ) 0.54 (CI 0.38-0.69, p < 0.00001)
and again there was significant heterogeneity for TMD (Q )
self-esteem. These changes represented improvements in
both self-esteem and mood. Based on the heterogeneity
findings six subgroup analyses were conducted.
Greatest changes come from 5 min of activity, and thus
suggest these psychological measures are immediately
min and half-day, but rise again for the whole day duration.
For self-esteem, the greatest change is for light activity and
is again greatest for light intensity, declining to the lowest
for moderate, and then rises again for vigorous activity.
Figure 4a and b show effect sizes for five categories of
habitat or green space. There are no great differences for
urban space, countryside and woodland habitats. For both
measures, waterside habitats showed the greatest changes.
Green places improve self-esteem and mood (mean of d
FIGURE 1. a and b. Meta-analysis of studies showing effect sizes and 95% CIs for changes in self-esteem and TMD after
participation in green exercise activities (change in self-esteem was calculated as the difference between the pre and
VOL. 44, NO. 10, 2010 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 3949
a larger difference (increase of 0.29 for self-esteem and 0.19
Table 2 shows the results where there are binary groups
large). Changes in self-esteem and mood were similar for
change in self-esteem than those with self-declared mental
though there was only a small difference for mood (d ) 0.53
compared with d ) 0.56). Table 2 shows significant within-
group heterogeneity based on starting health status (both
mood and self-esteem) and sex (mood only).
(<30, 31-50, 51-70, and >70 years). The improvement in
self-esteem declines with aging (the greatest change is for
the youngest age group), whereas mood shows an inverted
U-curve with greatest changes in the midage groups.
The results show acute short-term exposures to facilitated
green exercise improves both self-esteem and mood ir-
respective of duration, intensity, location, gender, age, and
health status. The six subgroup analyses suggest important
specific recommendations for the most effective dose of
nature and green exercise. 1. Exposure duration: both self-
esteem and mood showed greatest changes for the least
are likely to be qualitatively different activities, involving in
some cases camping overnight and in others significant
improvements declined with growing intensity of activity,
activity. This suggests that there is a health benefit from any
short engagement in green exercise. 3. Type of green space:
the presence of water generated greater improvements.
Although participants should be encouraged to undertake
outdoor activities in both rural and urban environments,
spending time near waterside (e.g., beach or river) or
participating in water-based activities may give a greater
benefit. 4. Sex: both men and women reported similar
improvements in self-esteem after green exercise, though
men showed a difference for mood. 5. Age groups: for self-
esteem, the greatest change was in the youngest category,
FIGURE 2. a: Dose response data for the effect of exposure duration on self-esteem. b: Dose response data for the effect of exposure
duration on TMD.
3950 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 44, NO. 10, 2010
will see more self-esteem improvements, and the middle-
aged from mood. The over-70 age group experienced the
least change, perhaps because those sampled were already
were limited. 6. Starting health status: the mentally ill had
one of the greatest changes for self-esteem improvements.
This suggests that the mentally ill should be encouraged to
undertake green exercise.
Exposure to nature via green exercise can thus be
conceived of as a readily available therapy with no obvious
for both intensity and duration showed large benefits from
short engagements in green exercise, and then diminishing
who are currently sedentary, nonactive, and/or mentally
unwell would accrue health benefits if they were able to
undertake regular, short-duration physical activity in ac-
smoking, giving up inactivity and urban-only living results
scale and randomized studies of different cohorts over long
time-frames to explore the dose of green exercise further.
All studies included in this multistudy analysis involve
exercise in green environments. The combined benefits are
thus assessed but the relative contributions of each com-
ponent are still unknown. Thus, there is also a need for a
field-based controlled study to analyze the benefits of each
element and assess whether there are any synergistic
outcomes. This has been demonstrated in a controlled
laboratory environment involving simulated green exercise
(12), but evidence is limited in the field. Overall mood effect
sizes for green exercise in this study are slightly larger (d )
0.54) compared with exercise in nongreen environments (d
The findings here are based on short-term exposures to
single interventions. There remains a need for longitudinal
multicohort studies to track changes over time. Important
activity has finished, and whether there are accumulative
effects following repeat exposures. The findings comprise
data becomes available future meta-analyses will be more
cross-sectional. The 10 studies were also analyzed over a
period of six years, so self-esteem and mood may have been
manipulated by extraneous variables which could not be
controlled for. However, the outcomes do suggest a new
a regime of doses of nature may be prescribed for anyone,
but will have a greater effect for the inactive or stressed and
mentally ill, or at presurgery (58) or for recovery (59).
Employers, for example, could encourage staff in stressful
workplaces to take a short walk at lunchtime in the nearest
FIGURE 3. a: Dose response data for the effect of exercise intensity on self-esteem. b: Dose response data for the effect of exercise
intensity on TMD.
VOL. 44, NO. 10, 2010 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 3951
park to improve mental health, which may in turn affect
productivity (60).A particular focus should be on children:
regular outdoor play brings immediate health benefits, and
may instill healthy behaviors early in life (61). Childhood
social and economic conditions also predict adult health
status (62), and outdoor free-play is vital for development
and cognitive skills (63, 64). Given the therapeutic affects of
green exercise (65), youth offender teams should engage
certain groups of young people more in outdoor programs.
Health inequalities could be reduced if attention were also
given to the importance of urban design for both private
and hospitals (14).
Although good self-esteem and mood are known to be
protective against future long-term health threats, these
mental health measures should also be assessed in conjunc-
tion with a range of further health markers, such as blood
pressure, cholesterol, stress hormones (e.g., cortisol), and
inflammatory markers (e.g., C-RP). This research has not
assessed the benefits of undertaking activities with other
people (the benefits of social capital), nor the benefits of
connections with animals (28, 66). It also does not assess
to long-term changes in knowledge and behavior, such as
engaging in outdoor activity, and therefore coming to know
FIGURE 4. a: The effect of typology of green space on self-esteem. b: The effect of typology of green space on TMD.
TABLE 2. Summary of Effect Sizes for Two Sub-Groups Where These Are Divided into Only Two Categories (Gender and Health
Q sub-groupmeasurecategoryd value 95% CIPNP
0.23 - 0.54
0.32 - 0.53
0.33 - 0.50
0.33 - 0.64
0.25 - 0.85
0.36 - 0.64
0.28 - 0.55
0.42 - 0.94
0.40 - 0.52
0.34 - 0.71
0.19 - 0.93
0.37 - 0.70
starting health status
3952 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 44, NO. 10, 2010
with nature could lead to changes in food consumption
environmental behavior and attitudes.
This study using meta-analysis methods suggests that
attention should be given to developing the use of green
exercise as a therapeutic intervention (green care), that
(green design), and that children should be given opportuni-
ties to learn in outdoor settings (green education). Some of
and physical challenges arising from modern diets and
forms of activity in green places.
A challenge for policy makers is that policy recom-
mendations on physical activity are easily stated but rarely
though could be substantial (42, 67). Policy frameworks that
suggest active living (69, 70) point to the need for changes
to physical, social and natural environments, and are more
part of life rather than a matter of daily choice (71). Simple
of their doctors. Accessing natural places for their health as
well as environmental services may aid these transitions.
We are grateful to Gavin Sandercock for suggestions on the
methods for meta-analysis, to Rachel Hine, Jo Roberts,
Murray Griffin, Marion Nolan-Ericsson, Graeme Willis, and
Sarah Pilgrim for some of the primary data collection in the
analysed studies, and to four referees for helpful comments
on an earlier version of this paper. We report that there are
no conflicts of interest.
Supporting Information Available
A brief summary of the instruments used to measure self-
esteem (Rosenberg Self-Esteem Scale) and mood (Profile of
Internet at http://pubs.acs.org.
(1) Millennium Ecosystem Assessment. Ecosystems and Human
Well-Being; Island Press: Washington DC, 2006.
(2) Weber, J. L. Implementation of land and ecosystem accounts
at the European Environment Agency. Ecol. Econ. 2007, 61,
(3) Centers for Disease Control and Prevention. Physical Activity
and Health; Report of Surgeon General: Washington DC,1996.
FIGURE 5. a: The effect of age on self-esteem. b: The effect of age on TMD.
VOL. 44, NO. 10, 2010 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 3953
(4) Be Active and Healthy. A Plan for Getting the Nation Moving;
Department of Health: London, 2009.
(6) Davis, A.; Valsecchi, C.; Fergusson, M. Unfit for Purpose: How
(7) Dobbins M.; De Corby, K.; Robeson, P.; Husson, H.; Tirilis, D.
activity and fitness in children and adolescents aged 6-18,
Cochrane Database Systematic Reviews 2009; Jan 21;(1):
(8) Healthy Lives, Brighter Futures: The Strategy for Children and
Young People’s Health; Department for Children, Schools and
Families/Department of Health: London, 2009.
of Science: London, 2008.
older people - a population-based study. Prev. Med. 2005, 40
(11) Hartig, T.; Evans, G.; Jamner, L. D.; Davis, D. S.; Garling, T.
Tracking restoration in natural and urban field settings. J.
Environ. Psych 2003, 23, 109–23.
(12) Pretty, J.; Peacock, J.; Sellens, M.; Griffin, M. The mental and
Res. 2005, 15 (5), 319–37.
(13) Ulrich, R. S. View through a window may influence recovery
from surgery. Science 1984, 224, 420–1.
(14) Mitchell, R.; Popham, F. Effect of exposure to natural environ-
Lancet 2008, 372, 1655–60.
(15) Takano, T.; Nakamura, K.; Watanabe, M. Urban residential
environments and senior citizens’ longevity in megacity areas:
Health 2002, 56, 913–18.
(16) UNFPA. State of the World Population 2007: Unleashing the
Potential of Urban Growth; United Nations Population Fund:
New York, 2007.
(17) Chiesura, A. The role of urban parks for the sustainable city.
Landscape Urban Plann. 2004, 68, 129–138.
F. G.; Groenewegen, P. P. Morbidity is related to a green living
environment. J. Epidemiol. Commun. Health 2009, 63, 967–73.
(19) Centers for Disease Control and Prevention. Physical Activity
and Health; Report of Surgeon General: Washington DC, 1996.
of Science: London, 2007.
(21) Wells, N. M.; Ashdown, S.; Davies, E. H. S.; Cowett, F. D.; Yang,
Y. Environment, design and obesity. Environ. Behav. 2007, 39
(22) Hartig, T.; Mang, M.; Evans, G. W. Restorative effects of natural
environment experiences. Environ. Behav. 1991, 23 (1), 3–26.
environments. J. Environ. Psych. 1991, 11 (3), 201–230.
(25) Pretty, J.; Peacock, J.; Hine, R.; Sellens, M.; South, N.; Griffin,
M. Green exercise in the UK countryside: effects on health and
psychological well-being and implications for policy and
planning. J. Environ. Plann. Manage. 2007, 50 (2), 211–31.
(26) Van den Berg, A. E.; Koole, S. L.; Van der Wulp, N. Y.
Environmental preference and restoration: (How) are they
related. J. Environ. Psych. 2003, 23 (2), 135–146.
(27) Pilgrim, S.; Smith, D.; Pretty, J. A cross-regional assessment of
the factors affecting ecoliteracy: implications for policy and
practice. Ecol. Appl. 2007, 17 (6), 1742–51.
and Our Place in It.; Earthscan: London, 2007.
capital, income inequality and mortality. Am. J. Public Health
1997, 87, 1491–98.
for community: inner-city neighbourhood common spaces.
Am. J. Commun. Psych. 1998, 26 (6), 823–51.
(31) Maas, J.; Verheij, R. A.; Groenewegen, P. P.; De Vries, S.;
Spreeuwenberg, P. Green space, urbanity, and health: how
strong is the relation. J. Epidemiol. Commun. Health 2006, 60,
(32) Matthews, H. S.; Lave, L. B. Applications of environmental
2000, 34, 1390–95.
(33) Pretty, J. N.; Mason, C. F.; Nedwell, D. B.; Hine, R. E. The
environmental damage costs of eutrophication of fresh waters
in England and Wales. Environ. Sci. Technol. 2003, 37 (2), 201–
(34) Bird, W. Natural thinking: Investigating the links between the
Natural Environment, Biodiversity and Mental Health; Royal
Society for the Protection of Birds: Bedfordshire, UK, 2007.
(35) Blascovich, J.; Tomaka, J. Measures of self-esteem. In Measures
J., et al., Eds.; Academic Press: San Diego, CA, 1991.
(36) Bernard, L. C.; Hutchison, S.; Lavin, A.; Pennington, P. Ego-
strength, hardiness, self-esteem, self-efficacy, optimism, and
maladjustment. Assessment 1996, 3 (2), 115–31.
(37) Torres, R.; Fernandez, F. Self-esteem and the value of health as
Care 1995, 16, 60–3.
(38) Hull, R.B. Mood as a product of leisure: Causes and conse-
G. L. Eds.; State College PA: Venture, 1991.
(40) Flory, J. D.; Manuck, S. B.; Matthews, K. A.; Muldoon, M. F.
Serotonergic function in CNS as associated with daily ratings
of positive mood. Psychiatry Res. 2004, 29, 11–19.
(41) Thayer, R. E.; Newman, J. R.; McClain, T. M. Self-regulation of
mood: Strategies for changing a bad mood, raising energy, and
reducing tension. J. Pers. Social Psychcol. 1994, 67, 910–25.
(42) Bockstael, N. E.; Freeman, A. M.; Kopp, R. J.; Portney, P. R.;
Sci. Technol. 2000, 34, 1384–1389.
Sci. Technol. 2000, 34, 1396–1400.
(44) Barton, J.; Hine, R.; Pretty, J. The health benefits of walking in
Sci. 2009, 6 (4), 1–18.
(45) Biddle, S. J. H.; Fox, K. R.; Boutcher, S. H. Physical Activity and
Psychological Well-Being; London: Routledge. 2001.
University Press: Princeton, NJ, 1965.
(47) McNair, D. M.; Lorr, M.; Droppleman, L. F. Revised Manual for
the Profile of Mood States; Educational and Industrial Testing
Service: San Diego, CA, 1992.
(48) LeUnes, A. Updated bibliography on the Profile of Mood States
2000, 12, 110–13.
Activity and Psychological Well-Being Biddle, S. J. H.; Fox, K. R.;
Boutcher, S. H., Eds.; Routledge: London, 2000; pp 63-87.
Clin Trials 1986, 7, 177–88.
meta-analyses. In Cochrane Handbook for Systematic Reviews
Eds.; The Cochrane Collaboration: London, 2008.
and Review of the Scientific Literature; National Health and
Medical Research Council: Canberra, 2000.
(53) Higgins, J.; Thompson, S.; Deeks, J.; Altman, D. Statistical
heterogeneity in systematic reviews of clinical trials. J. Health
Serv. Res. Policy 2002, 7 (1), 51–61.
Annals Intern. Med. 1992, 116, 78–84.
(55) Haskell, W. L.; Lee, I. M.; Pate, R. R.; Powell, K. E.; Blair, S. N.;
Franklin, B. A.; Macera, C. A.; Heath, G. W.; Thompson, P. D.;
Exercise 2007, 1423–34.
(56) Berman, M. G.; Jonides, J.; Kaplan, S. The cognitive benefits of
interacting with nature. Psychol. Sci. 2008, 19 (12), 1207–12.
self-selected workloads: implications for theory and practice.
J. Sports Sci.Med. 2003, 2, 77–87.
(58) Diette, G. B.; Lechtzin, N.; Haponik, E.; Devrotes, A.; Rubin,
pain during flexible bronchoscopy. Chest J. 2003, 123, 941–48.
(59) Pierce, J.; Stefanick, M.; Flatt, S.; Natarajan, L.; Sternfield, B.;
Madlensky, L.; Al-Delaimy, W.; Thomson, C.; Kealey, S.; Hajek,
women with high vegetable-fruit intake regardless of obesity.
J. Clin. Oncol. 2007, 25, 2345–51.
(60) HSE. Self-Reported Work-Related Stress and Workplace Injuries
in 2006-07; National Statistics: London, 2008.
3954 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 44, NO. 10, 2010
(61) WardThompson,C.;Aspinall,P.;Montarzino,A.Thechildhood Download full-text
factor: adult visits to green places and the significance of
childhood experience. Environ. Behav. 2008, 40 (1), 111–43.
(62) Wells, N. M.; Lekies, K. S. Nature and the life course: pathways
from adulthood nature experience to adult environmentalism.
Children Youth Environ. 2006, 16 (1), 1–24.
(63) Burdette, H. L.; Whitaker, R. C. Resurrecting free play in young
children: looking beyond fitness and fatness to attention,
affiliation and affect. Arch. Pediatr. Adolesc. Med. 2005, 159,
(64) Learning Outside the Classroom; Ofsted: London, 2008.
(65) Hartig, T. Green space, psychological restoration and health
inequality. Lancet 2008, 372, 1614–15.
Farrell, M.; Meltzer, H. Social support networks and type of
Med. 2003, 33, 307–18.
(67) Promoting Physical Activity for Children and Young People;
National Institute for Clinical Excellence: London, 2009.
(68) Wanless, D. Securing Our Future Health: Taking a Long-Term
View; Department of Health: London, 2002.
(69) Sallis, J. F.; Cervero, R. B.; Ascher, W.; Henderson, K. A.; Kraft,
M. K.; Kerr, J. An ecological approach to creating active living
communities. Annu. Rev. Public Health 2006, 27 (1), 297–322.
(70) Our Natural Health Service; Natural England: Peterborough,
(71) Matson-Koffman, D.; Brownstein, J.; Neiner, J.; Greaney, M. A
site-specific literature review of policy and environmental
interventions that promote physical activity and nutrition for
cardiovascular health; what works. Am. J. Health Promotion
2005, 19, 167–93.
VOL. 44, NO. 10, 2010 / ENVIRONMENTAL SCIENCE & TECHNOLOGY 9 3955